Treatment devices of electromagnetic wave irradiation type which treat tissues by irradiating body tissues such as the skin with electromagnetic waves to treat the tissues have been conventionally known. For example, Patent Document 1 and Non-patent Document 1 disclose treatment devices which irradiate skin with RF waves. In these treatment devices, with radiation of RF waves onto the skin, regeneration of epidermis is stimulated by warming the skin, or regeneration and growth of collagen are stimulated by warming the dermis.
A treatment device of electromagnetic wave irradiation type is structured to include a power supply device provided with an electromagnetic wave source and a power supply; and a treatment tool called a handpiece connected to the power supply device. The handpiece is provided with an irradiation unit which radiates electromagnetic waves to a treatment target such as the skin. For example, when RF waves are used as electromagnetic waves, a pair of electrodes is mounted on the irradiation unit. After the pair of electrodes is brought into contact with the skin, electromagnetic waves such as RF waves are transmitted from the electrodes. The electromagnetic waves emitted from one of the pair of the electrodes reach the other electrode via the skin. Skin tissues in the path of transmission of the electromagnetic waves in this process are warmed.
In this occasion, even if a target region is smaller than a region which is covered by the flow path of the electromagnetic waves, basically, the whole path is warmed equally with the target region. It should be noted that a patient may feel pain by the temperature rise of body tissues. Although suchapain is endurable without anesthesia, there is a demand to reduce the size of the regioncausingthepaininconsiderationoftheburdenofthepatient. Thus, in Patent Document 1, a cooler is mounted on a handpiece to restrict the temperature rise of the tissues outside the target region by bringing the cooler in contact with the skin surface.